CBS offers some answers, and some advice: "There is no 'penis bone,' but you can break your penis all the same. It's called penile fracture, and it's not a subtle injury. When it happens, there's 'an audible pop or snap,' Montague says. Then the penis turns black and blue. And there's terrible pain. Penile fracture is rare, and it typically happens to younger men because their erections tend to be quite rigid. Here's how to avoid penile fracture: don't use your penis too roughly. A common way that penile fracture happens, Montague says, is when a man is thrusting too hard and fast during sex, and slams into his partner's pubic bone. Also, a woman who moves wildly while on top of a man during sex can break a man's penis."